<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        body {
            background-color: #bbb;
        }

        #canvas {
            background-color: #000;
        }
    </style>
</head>

<body>
    <canvas id="canvas" width="400" height="400"></canvas>
    <textarea name="" id="log" cols="30" rows="10"></textarea>
</body>
<script src="./utils.js"></script>
<script src="./arrow.js"></script>
<script src="./ball.js"></script>
<script src="./ship.js"></script>
<script>
    window.onload = () => {
        var canvas = document.getElementById("canvas");
        var context = canvas.getContext("2d");
        var log = document.getElementById("log"),
            ball = new Ball(),
            vx = Math.random() * 10 - 5,
            vy = Math.random() * 10 - 5,
            friction = 0.1;

        ball.x = canvas.width / 2;
        ball.y = canvas.height / 2;

        (function drawFrame() {
            window.requestAnimationFrame(drawFrame, canvas);
            context.clearRect(0, 0, canvas.width, canvas.height)

            var speed = Math.sqrt(vx * vx + vy * vy),
                angle = Math.atan2(vy, vx);

            if (speed > friction) {
                speed -= friction
            } else {
                speed = 0
            }

            vx = Math.cos(angle) * speed
            vy = Math.sin(angle) * speed
            ball.x += vx;
            ball.y += vy;
            ball.draw(context)
        }())
    };
</script>

</html>